Reaper forgetting various config settings

[Passionate Man]

A couple of weeks ago my Win 10 PC blue screened on me (I think the first and only time it's happened) whilst in the middle of a session with Reaper 6.13. Ever since, after opening a project it forgets to "Enable" my MIDI In and Out devices in the MIDI Hardware Settings menu. The devices are all recognised and work perfectly once enabled, it's just that I'm now obliged to enable them each session.
Also, little details such as "Pre-roll before recording" keeps defaulting to unchecked, whereas before it would stay checked (my preference), and in Media Item Properties, position and length default to "Time" as opposed to "Beats" (again, my preference)
Whilst Reaper is open all amended settings are maintained (when switching projects) but upon restart it's back to zero. Haven't been able to find anyone with the same issue; most seem to be problems with MIDI devices simply not being recognised. Tried messing around with REAPER.INI a bit (I really don't have much of a clue here, but took care not to damage anything) and no dice.
It's getting on my tits...